A Retrospective Analysis of the Relationship Between the Result of BRCA1/2 Genetic Testing and Surgical Method Selection in Japan

Background: We studied the extent of BRCA1/2 genetic testing to help select the surgical approach for patients with breast cancer in Japan remains unclear. Patients and Methods: The study subjects were female patients with primary unilateral invasive breast cancer considered as candidates for breast-conserving surgery who underwent preoperative BRCA1/2 genetic testing. A retrospective analysis was performed on the results of BRCA1/2 genetic testing and surgical method selection using national registration data from the Japanese Hereditary Breast and Ovarian Cancer Syndrome Consortium. Results: Our study included 318 female patients. Among these patients, 23.7% of patients with BRCA1/2 mutations and 61.8% of patients without these variants underwent breast-conserving surgery (P < .01). Among the patients with BRCA1/2 mutations, those who chose breast-conserving surgery tended not to undergo risk-reducing salpingo-oophorectomy (P < .05). Among the patients with BRCA1/2 mutations who underwent mastectomy for the affected side, 31.8% received contralateral risk-reducing mastectomy. Patients diagnosed with breast cancer under the age of 50 years were more likely to have contralateral risk-reducing mastectomy than patients over the age 50 years (P < .05). Conclusions: Patients with BRCA1/2 mutations tend to choose mastectomy. However, it is speculated that the final surgical method selection is made in consideration of not only the test results but also with careful consideration of the patient, taking into account other factors including individual values for risk-reducing surgeries and the age of breast cancer onset.